Spray gun valve



Jn. 20, 1 953 w. I AMMIMANl 2,626,122

SPRAY GUN VALVE Filed July 3, 1951 f7 .16 i4 j Je 9 INVENTOR LEWISWTIAMMIMAN.

ATTORNEY Patented `an. 20, 1953 UNITED, STATES vPATEIW OFFICE 2,626,12zsritiY GUNjvALvEI Lewis W. Lammiman, Toledo, Ohio', assign'or to The DeVilbissCompany, .Toledo,fhio, a corporation of Ohio Application "J uly3, 19512', SerialeNo. 235,013

4 Claims.

lthe air jets is reduced or increasedby closing orv opening movement ofthevalve.

As usually constructed this valve Vhas a vtapered 'inner end which seatsWithin the air passage, a threaded shank by which it is rotatablymounted,

and an external knurled head' for manual adjustf ment. In'order toprovide a' broad range of adjustment a relatively'fine thread isutilized. It is thus possible to set the valve for a very particular owof air that will shape the spray pattern 'most suitably for a certaintype of surface.

In many spray hishing operations the character of the products beingcoatedis such that a single lwidth of spray vis satisfactory for allpurposes. However, in otheriinishing'proeesses, there are occasionalsurfaces of restricted area, for which a wide spray pattern, Vselectedfor". a major part of the coating work, is not suitable.

vSince*excessive 'Waste'frm overspra'y orit'oo heavy a vcoatingresultsfrom the Iuse of too'wide a spray pattern, under 'such circumstances itis desirable for the operator to temporarily screw the spray width valveat least part way towarda closed position. He must subsequentlyAcarefully openy it again to the predetermined setting considered bestfor the predominant type'of surfaces. Because of thev ne thread on thevalve shank, considerable rotary movement is' required inthis closingand opening of the valve and valuable time is lost in theaccompanyinginterruption of thel sprayingoperation.

The purpose of my invention is 'the provision'fof :af valvestructure-for controlling theY air deliveredto attening jets in a spraygun in `which thefadvantage of close adjustment is retainedfand which inaddition has mean-s'for `easy and rapid manual closing and self-openingmovement of the valve with stop means limiting the opening movement tothe valve position previously selected for normal use.

This improved action. is secured by mounting the valve for both gradualvthreaded adjustment and independent sliding axial movement. This isaccomplished by having 'an unthre'aded valve shank fitting snugly' forrelative'axial'movement within an" -exteriorly'fthreaded-brota',`1',"ableA Tsleeve` In order to secure spray pat- (Cl.25k-2l the exterior end of sleeve 22 is the knurle'dhead andprovidingbetween the valve shank andfsle'eve a longitudinal slot and pinconnection'.

An embodiment of'my invention is hereafter described in detail andvillustrated in the accompanying drawings in which- Figure 1 isa'central'vertical longitudinalse'ction of a spray gun-incorporatingthe-invention;

Figure 2'is an enlarged longitudinal section of the valve assembly takenon the line 2--2 of Figure 1;

Figure 3 is'ra perspective-viewer the horse Shoe 'lockl washer whichholds ythe'- packing spring'4v in place; l

Figure 4 is a perspective viewwith a portion broken away of the valveassembly fcasin'gl;

Figure 5 is a perspective view Vo'f the valve'position adjusting sleeve;vand Figure -6 is a sectional -viewv v taken oni the `line 6-6 of Figurel2 'through lthe valve Ishank'.

The spray gun of Figure l--is a'fc'onventional design Vto which myinvention has'- beenadapt'ed. Ithas `a depending handle I` in whichthere isfan air supply passagev v21S The travels therethrough past airvalve'f3'whichisA opened by. rearward movement of the"trigg`erllag'ainstl the extjeriorly extending ivalve spindle 5i The.V air. thenhows upwardly.- from the val-ve chamber `through outlets. O-ne is aforwardly continuingpassage into the airv partitioning. inernlmer `I 0;The other outlet is* thef annular chamber lvl b'ehind'vthe 'member-1B.Theoutlet passage: yilis for air travelling'to `the'horr1s-l2-o'f theair cap I3 vto form opposed spray flattening'jets. The air from passage9 reaches the horns by way of the encircling chambery Ill, 'a .seriesofI ports I5 throughia flange of ttheinember I0; andhen'ce into annularchambeil behind the bores Il into the horns. .The outlet, chamber H isyfor 'primary' atomizing air vvliiclriV 'travels' forwardly'- through an"annular rse- "ri'es loi'passages I8 intothe spacef FQ'betWeen-.the

spray material tip 20 and theair cap' .|3. From here' the air flows voutthe center oricef ofthe air'cap. in atomizing association withrthe spraymaterial discharged' from' tip '20.

Into the rear end of bore 8 is threadedly mountedthe valve casing 2 I.Extending through the' casingr 2| and threadedlyv connectedy thereto foraxial adjustment the valve sleeve 221. On

l2i! for manualturning and axial positioning of the sleeve: Throughthesleeve 22 .extends the shank 24 o'fthe valvda-f.A 'Thershank hasfi-'Mose but@'slid'abie'iitffwith the1=fsl`eeve.-v The valve 25 sitionedlongitudinal slots 3l in valve sleeve 22.

A spring 32, lodged within the enlarged bore 26 of the valve sleeve 22,is compressed between the bore shoulder 21 and the forward end of thethumb button stud 30. Through the effect. of the spring thrust the valveshank 24 is yieldably held rearwardly in respect to the sleeve 22 to theex.-

tent of movement permitted by the pin and slotv connection between thevalve shank and sleeve. Accordingly the ends of the pin 29 are normallypressed against the rear ends of the slots 3 I.

Through the threaded engagement of the sleeve 22 with the xed valvecasing 2| axial movement of the sleeve 22 is secured by manual turningof the knurled head 23. Because of the pin and slot connection betweenthe sleeve 22 and the valve shank 24 and the effect of the springholding the pin ends at the ends of the slots, axial movement of thesleeve varies the position of the valve 25 in respect to its seat. Theamount of air reaching the horn ports is thus controlled and maybepredetermined to accommodate the type of surface being finished inrespect to the width of spray desired. Y

When a narrow surface is to be coated and it is desired to momentarilyreduce the width of the spray pattern from that selected for largesurfaces the operator depresses the thumb button with the thumb of hishand actuating the spray gun and thus pushes the valve 25 toward itsseat reducing theflow of spray flattening air from the horns. Undertension of the spring 32 which is temporarily overcome by the thumbpressure the valve is returned to its selected position when the thumbis removed. A spray of proper width is thus again delivered for coatingthe general run of work, as the return of the valve shank does notdisturb the rotary position of the sleeve by which the preferred valveposition was previously secured.

For a long period of coating surfaces of limited v4dimensions the valve25 may be forced to its seat by turning sleeve 22 sufficientlyforwardly. The length of the threads between the sleeve 22 and thecasing 2l -is suicient to permit this action.

To prevent leakage between the sleeve and the valve casing, packing 33is positioned therebetween. It is held against an inner annular ange 34of the casing 2| by spring 35 which is held in compressed prelation tothe packing by the horse-shoe lock washer 36. The latter is postioned ina groove 31. In order to lessen the twisting effect upon the spring 35from rotary movement of the valve sleeve 22, a loosely mounted washer 38is inserted between the end of the spring and locking washer 36.

From the preceding it may be understood that the slot and pin engagementbetween the valve .shank and sleeve in association with the spring 32.and the threaded mounting of the sleeve provides means for both gradualadjustment of the valve shank and the surrounding sleeve is utilized inthe preferred embodiment, it is realized that there are analogousstructures which would serve as well. For instance a groove of suicientdepth would function as electively as the slot. Then too, a pin orfiattened tongue could be feasibly substituted for the screw. It is notconsidered that such replacements would depart from the spirit'of theinvention and that slot and screw as herein specified should accordinglybe interpreted broadly.

Also, it may be well to point out that it is not essential that the slotbe in the sleeve and the pin or screw be inthe valve shank as thereverse positioning would work as well. In addition, it may be observedthat the valve shank could have a threadedengagement with the sleeve andthe latter a slot and screw engagement with the rod without any loss infunctions over the preferred form. For this reason the scope of thisinvention is not considered limited to a particular location of suchengaging structures.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a spray gun air valve, means providing an air passage, a valveseat within the for- Vward end of the passage, a valve mounted for axialmovement toward and away from said seat, an interiorly threaded casingin fixed position at the rearward end of the passage, a freely rotatablehollow sleeve threadedly engaged within the casing, a shank integralwith the valve and extendingl rearwardly through the hollow sleeve, aconnection between the shank and sleeve formed by a pin and alongitudinal slot adapted to provide limited relative longitudinalmovement between the shank and the sleeve, an annular shoulder on theshank facing forwardly toward the valve seat, an annular shoulder on thesleeve facing rearwardly away from the valve seat in opposing relationto said first shoulder, a spring compressed longitudinally between saidshoulders adapted to thrust the valve shank and valve away from saidseat to the limit of movement permitted by the pin and slot connection,a rearward exterior element onV the shank for receiving temporary manualpressure to thrust with straight line movement the shank and the valvein opposition to the spring thrust toward the valve seat, and adjustingmeans on the rearward portion of the sleeve for manual rotation andaxial movement of the sleeve upon its threaded engagement with thecasing to vary the normal position of the valve as determined by thelimit of the spring thrust movement permitted by the pin and slotconnection between the shank and the sleeve.

2. A spray gun valve as set forth in claim 1 in which the rearwardexterior element on the shank has a hollow stud part into which the endof the shank extends, and the pin of the pin and slot connection extendstransversely through the shank and stud part to secure the element tothe shank with the ends of the pin extending further into slots inthe'sleeve to form the pin and slot connection between the shank and thesleeve.

3. A spray gun valve as set forth in claim 1 in which the sleeve has abore portion closely fitting the valve shank and a rearward enlargedbore portion, the rearward enlarged portion providing a housing for thevspring, and the shoulder ofthe sleeve against whichthe spring is com-LEWIS W. LAMIMIMAN.

6 REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date Warter July 19, 1921 PetersonDec. 19, 1933 Pellar Mar. 9, 1944 Peeps May 17, 1949

